[m-rev.] for second review: Add future datatype for concurrent and parallel programming

[Peter Wang]

On Thu, 9 Oct 2014 13:32:58 +1100 (EST), Julien Fischer <jfischer at opturion.com> wrote:
> >>
> >> impure_init needs to be (1) a function and (2) defined in the public interface,
> >> since users require a way of initialising semaphore valued mutables.
> >
> > Why?  If the rest of the semaphore library was pure I/O code was this ever
> > used outside of the standard library?
> 
> The version history is a bit confused because these modules were
> originally moved out of extras directory back when we were using CVS.
> It looks as though the purity of semaphore.new was originally incorrect
> and later corrected by being made impure.  (At some point we changed
> all the 'new' predicates to 'init'.)
> 
> > I'm not if we do need to provide such a function, at least the
> > deprecation will allow people to continue to use this and we can find
> > out if it causes a problem for anyone.
> 
> I think mutable initialisation is a legitmate reason for this to be
> provided.

Bug #223

Peter